> From: discuss-boun...@lopsa.org [mailto:discuss-boun...@lopsa.org] On > Behalf Of Trey Darley > > Say you've got a simple ascii text file, say, 250,000 lines long. Let's > say it's a logfile. Suppose that you wanted to access an arbitrary > range > of lines, say, lines 10,000 - 13,000. One way of doing this is: > > <snip> > sed -n 10000,13000p foobar.txt > </snip> > > Trouble is, the target systems I need to exec this on are ancient and > don't take very kindly to the io hammering this delivers. Can you > suggest > a better way of achieving this?
Inside a process, the process can seek() to a specific byte number in a file, but if you're looking for a specific range of line numbers, and the line length is variable, then there's no way to jump directly to a specific line number. The only option is to do as you're doing - read from the beginning of the file, and scan for \n characters and count line numbers. It's possible, maybe, that sed has an inefficient algorithm to do this. But I doubt it. Unless you can get the data and the workload to be on the same machine ... or you can find a way to specify a byte range instead of a line number range ... I don't think you're going to gain much over sed. _______________________________________________ Discuss mailing list Discuss@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
